This was a multicenter, randomized, open-label trial of low-dose intrleukin-2 (il-2) in combination with continued antiretroviral therapy versus antiretroviral therapy alone in HIV-infected subjects with cd4+ cell counts 300-700 cells/mm3 and >/- 2 consecutive months stable antiretroviral therapy immediately preceding enrollment. Initial treatment was for 24 weeks. After the primary analysis at 24 weeks, there was a 24 week crossover of treatment assignments such that those subjects who initially received antiretroviral therapy + il-2 continued antiretroviral therapy alone, and those who initially received antiretroviral therapy alone had il-2 added to their regimen. Further clinical and laboratory monitoring was performed during this period.